SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '873669ba656e0d993421edf28f2c59967afdd074c9d4d8c174ddfd953312a24e' 
  AND token = 'WT7HqtiLeiLryVVBlck8pdaWBRlMt97PRsSpC/toQbI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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