SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b25aa088a4eeec175e7817e97f8f8a1bb37490d2c8c9e319346c2e7c79739c84' 
  AND token = 'Bd/zB1/tuCCqJG3piXOVKvH4ZIl1lwSRitdjWzRHl6Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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