SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '83049c5e579ea37389610ea29f84e9b975b84d14b62baca7292255faf97b71c1' 
  AND token = '/IlSb6pDKTdLotcOT/AC30pGzbdacRu1cT94SOe4H2Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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