SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c4a55d540b782e836c149c736f87a6aa2b25835e165ee7b2a3969a11ed8af938' 
  AND token = 'wpwvNMFCH4JRZhUCtBuH4gquU1qvN6aqEjxc40O2GZ8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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