SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '2c6fdbdcf727fc120bae94c20995924dc593c0b57e792d3d7d8afb6f4a4a0df3' 
  AND token = '6/PkYBmDWH8oxbbZJCMaBPvAOb0yTtBzgWnYj5xhfnI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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