SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a43f734bcf0fca98f8f5736b93ef918587831d0545ec936178ef6be8eeb0c88c' 
  AND token = 'MAx6MCcy9+jRYLOTePdgZdrFRbEm7RRq3cLHAfLWUQs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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