SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '931924b0e4584c9e7e340e44214240178f23bd0e8e39f9602ad914e913fc48ef' 
  AND token = 'brGgI7iB+0wfIZCyVzK2/kcJYDh+0OlYtZ+o16fDn8c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}