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SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '368142a3804865fa7cf4403e693bf7867caff99663d173f09b569d2a00923a39' 
  AND token = 'umOR5dXumvZ05YN8kZ4TudJSNlF2uEKq+3yEqytmiYc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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