SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5f245b63f377a91a4d731864dfb615c8f84af91c15e40fe7836b111eb1cb7e7d' 
  AND token = 'RQP/DhmIkw0ssuTqKuqz3EK8h1+5J1V2QKwfl86lgGg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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