SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '45fbf2e45656f8c76b9f125d43e6985cd11d7bd9d4cfbd75f0fbf40dd1293594' 
  AND token = 'JEXu0Mk+PP415sPImaFf32OzZAY/0BdbNr8k/C+jGqg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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