SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dac19b6a8893e47c7c6dc9c37006964dfdf434c6dd755b8413b9c055441c6f62' 
  AND token = 'Jr27gh+2EkzzPejx5+W9HGPi5CwBJDnuI/i0g1X7ZkM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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