SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2ba0239b3c44e5bce77015a899b4978f267fea50c5863b7e91169bb49826dfc2' 
  AND token = 'RVsthxAcuNqQb6BoCEYxEOKh6APSjh4GLyuWPS0dzhg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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