SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3c89f595c6017a26a172383168d7ab19be4f73d1ea7e9eaa73065838eac927b1' 
  AND token = 'KM/O1sczoLoAO4i8/mh8x8o+BOHeM52/4Ksm3gIfT64=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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