SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e9cc7e4a64dd8ebd9f9de55975f5fa7520fb006a01bcde04280941de3e55cb08' 
  AND token = '47ScSrHtxMfoc6m+jTTB7v3RPkcmHC8gf6+otvUOEkk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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