SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5b9e99bfa6b54613d102b2530c21717017688b1f081a14338c7ea15bbaba54c5' 
  AND token = 'jK545PQ03iIUHndwQzBLeF6TrDAuqfchJ/cZ5/F8wvs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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