SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f913cdf067ea3a53804b857d4c94321b26eee52f73f8f54d78e46e1364e58136' 
  AND token = 'fpRhLLIBgG3gk9j4XDvdGN42Smw5NGWm7+CEVDJPWWA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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