SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b0550249e4b199c2a5e9ebb77ff3630802bfa926ed188acd2d824737569f52ab' 
  AND token = 'SXgvayNIxPSijgYgqoaBdB4KT9JUEiLtRdpriMQRSo0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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