SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ae3b2a088db418ec97aba8cbe33f1ee503157d961d922ffd2a6112ea7b26306b' 
  AND token = 'zbevNHQY6mHcYvggwUClQcy9mHGFHnNydlavZrv+rVY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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