SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '80e43e59ecd7bc00860335d98f2555c994a24b626548cd94c2f6022e8bcd5e2e' 
  AND token = 'Zlhi/S9lRJV8Y0qOeFbgjZe+newserMFTtd46rHm3vQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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