SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a349370ce69b7e30e549ad720e1f53aa83ea1018fa7f2e8373ae4ce4bb54c670' 
  AND token = 'PL40wqn+WdOHf+T8YXZRBVqlRCgNImDp57BFfnHhQow=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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