SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '580563dc4ee367ffb72812b0d6e9e44adfb49b6274a80e2a9a9c9e10984f2930' 
  AND token = 'z/4AmICiz5rgzdEFY8DZCUze2phbBoOdRIneYMZLFr0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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