SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c7bd1fbe432b9ef14fbe8c647adc94e714396c56a3cad74a5ff136f081ef6eda' 
  AND token = 'VhKjjCwTg1jDppEt2FIUnDE3+6BdEQakAzPx9+k4OAY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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