SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b19c582cb2a8e4481cbebaea9f437f8ecfcd5abfbadbcd41cc22efeae7246b63' 
  AND token = 'llGp66N0WZJOeW0mO+hT72ClUjFQxwi2P7uGUE3k3L4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00057

JSON explain

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