SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4b54e69fae372023cceedccf70d30fef35e32b3db1334f172833ce33ddfa6eed' 
  AND token = 'NOzlpYcqBsxD8M2C9BZ8VCIeBSizWqtmCXLHrbldV9Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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