SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '342055c6c7be36053a3a229c554367a63e22c5cc85a0f3aa90dfe0c4a5817be7' 
  AND token = 'BkKE5I0v8qAPyQ7wO6cs4SYJt9H5903qoauLxi+bRsA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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