SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e3c93eafc57dfe5c32fd807f759e6cf4c9a45067710b9c798b4a42d9ab7b31be' 
  AND token = 'zvwBzxYBeLPg3BKCRpgIrz/iblFUGJbsi58F6Bxtw6U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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