SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '45bf47c844d6055c8cc64b317bb4446f1b6c70e2dc0fcd069f5370926970f958' 
  AND token = 'twnGUQ9EoNUhAIPn6S2QF3wIW1KimdKCVV14ioOBb8c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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