SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c4773de73c927f05b2fa59f2a12f9f013313a319960d463b7946b49e2f32af51' 
  AND token = 'Gjwwyap02y4fj1lG04vYXE9/UukBbHz5ENNqx9Nw0oY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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