SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'efc7accea25aa0713918e22face58278f9082eee268b4fc49e8f9563cb6bffe3' 
  AND token = 'IZu8hABkB2qVcN69W031szr6r42LyVAKBaPDn+D1ekw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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