SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '27d30e3423b41937e9badcfba73d9e9c5d3f6b5e23800b4f4d2209252554fede' 
  AND token = 'CsBjGmI+pVfvLEQ/+7ifGtAZncy/Qz0JjgwC3QIf5sk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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