SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3976f08e7fde773905eeb66700e45e5b241f0a18bd3447f692f89bf7d2f31a6f' 
  AND token = 'Hs//dFv9NvvUsqhtMAfeiEkRvtheSm7mfM2FJa9/Dw8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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