SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '14fa83af832767f8c76ee33251aa57da13b3489347454b5bbdeb86186638ba8a' 
  AND token = '+IZ9wU02rPi1Xy0zstCUmemSlOtUY8zYaYfcA8lH9LI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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