SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '55d2f3a7ea4c647689ac14512bcdf25f9d93d66d1456c7ab3ebf99d925072810' 
  AND token = 'AjZTJi+hRtoapN33/mB9limXgJ6q43DpCA+3/U2xzBY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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