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SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'e43f74fbeb9a3eccc04f32cfd5e593dbd0870ea5ce0bd3954951fd81c5fb5eec' 
  AND token = 'h0dZnekz5vF3hEkqQj2Om0b7JTIodb3g2DyVlNkY/2A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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