SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '00b158960fdc3d2b7f6b1e75eb91324325810a3e72be4bde8b228fa481aac628' 
  AND token = 'uKjYHR2dP568OlKNWO2JoyFyhhEpCQLeVyeWiGvD/WA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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