SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '710d07243c73566f1b7ad2f5bc65274f9ee73aec53e1a12925a085137bae7d55' 
  AND token = 'kGLryzZkOg0gdel2787kZEUL0ttjkXmygdXl1Jo0zXE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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