SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd21be8c5a5361a65377905383b20c0c2d69d785e7308ccfb0ae0d9e762cbdb43' 
  AND token = 'BxwlMVYKwEqI9KxJBZzp980FhFI4rlAJrm+G1CqZT9A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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