SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a12699d9819f61b5bec86c738ec3586f1dc4b287a77c19231b1acf0c05c6c740' 
  AND token = '49YgsyiEse5WL3KjSuYa5Oi6a0kxkM4/DAhTDo2r1Xk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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