SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '02cb1c486b0ad663550be75c73d81609b914ea5d8aafdd7010c3f69da099548d' 
  AND token = '+KK5/GOKqae9ZwAFQNbBw+plmOHjmQQ5lWDce8NNNnY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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