SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5fe59f8eca16af2cd580989a8c413fc97efaea55ffbddfe1438273d078aa5e24' 
  AND token = '1uSNUEAFJ9J4gSsggkHojy2OdTlBprVf9A+uZABdeVU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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