SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '10b86908d72e7fd66410aec073daea8b17b4785ce5494a4cc5b66bef5d04c6de' 
  AND token = '5r6MEJC/Jmidkivj3fGoVKEhMrCNQmbSoPHzL03aXew=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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