SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '65141666a1337709e773fdf6a55918212d6acfd807e59b4cfd062d3f4f13fc12' 
  AND token = 'iVFVuKUzCzKn7fHk3fbWLgC8Y81RakqOmvXCgUzgMJQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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