SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7d9b52be120dca47c5bdf004c6f1787b3ecfaa583253e2cf4fc36bd240a709b9' 
  AND token = 'GoeBIZfjQg5Qh6BJV4IJPiUgb7T3sVwyIRCqMFKVGIY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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