SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a0fef9a7d075fd0ee314c85a870ad51cb1077f4dde8574b5742db23fc61dc3c3' 
  AND token = 'xlHktPNuAa/0nuSplYQEJYEPAkSAFxwoO/xbVd6HSYk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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