SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '026767b29f2da8fa317209b06e086635f5679844c45ca715118a94a3ec5f2d99' 
  AND token = 'tV8Spclalyj/ihiyO3UHoTva2Wj2JeYWnkTC6G7dApo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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