SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '04fcb196c641faa1487c2ece2f2ff08993523f476c03cee6988355e47d9de19b' 
  AND token = 'gl0hcRLd3EzN7RkIXqdmUjEVQMChgGur++knHu/BDTs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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