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SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '6f5dd6f192dfe5e8d38302397ca2d9629ef9a1a5ef2528f38ce214ba1c695adc' 
  AND token = 'm5l3OLMqTQajAEj8TQ1w1Ko0+n9AeGu3EfBJJ/LnVno=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}