SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '41784edbb03c8db6255b151db2c8e1913c1470d8365a8ee82c6b4df349b68bfc' 
  AND token = 'fz8ttEMERKqtiQ7Cda88bjRo8Q+C2S3y9NTAagN3y8I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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