SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ce586c6d4381818a69e99c33ddce47e51fea97d31499ed6865a651093605abc7' 
  AND token = 'NjuJL6LhZGX1AMIKIcLHGKA/vQOg5LhRQxXcpxY80M0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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