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SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'b25e29301adea10995d05264249c81c3846548a7420abb7a7c7b6766a9a92458' 
  AND token = 'duwHtFUOCRAI4x+dO2XD2KIBiamUsa1+nZodBkB2uxg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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