SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2b455b59747ca1741c09b037f116e44cc2cc50304c61305ba3dc09d84b5843db' 
  AND token = 'AUBfJwZJdicHfJMbRCyh09V/MhZeyJdOEk9Xwvbc/6k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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