SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd69d1ec63b120706ffe379b411a63ca89e66bc449cbb159bddfd3dbc14dae771' 
  AND token = 'MDX5vsHnbAOcyICoLC7TT8fnw6kiU/BhchwV4Y3djwI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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