SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'acee27d470e986bd4f0b7f38b94ce61123b84afa8eea2c6a538124990cb35af8' 
  AND token = 'GUMNbmzS3WKkAJ1BOAK8Hhjl+LY/n6e+Ap6BvqrRcmI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00010

JSON explain

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