SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ce5ca0f7e0f578631abd99e94d931d0cef13dffc98199eb3d4d80604d650ab53' 
  AND token = 'RBQsxr1VVOr9CLV3t2DxQFRReDlpelHH226MnNDLUIY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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