SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'e7b546b112ab854517d7eff1b2ff486f2ade3a148300a93e99e5d7f0c59c63d5' 
  AND token = '+JztMq+Se5Ag4Ax7aAZps0mTA5uNbv3lKOKhv+b5nFw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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