SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'fa3f2a6d735a0b69e40795a36ac0023e4b5579a57257479916e2ab340673aa25' 
  AND token = '2vOVtrKZVdb+0yd2bd0qh72FgZjVv9FSdJ6c3HZhEmE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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