SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '443f0d426831e3e5043b47f900db4a409173cc9de73bf770b72f652494bc2396' 
  AND token = 'PYbiTzhsbwez613Nx1Lx8EO+dDE0qc8m7DkMg1QymxQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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