SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'ecdb38857cc5e3c18307befd948b54b330e503bf931564a3da477abba888b3cf' 
  AND token = 'UqH8LWov3md6Gsaf/DlojOYaIhvGjQuUjMAQejIzlcc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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