SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '78e92875e8bcfb8e741941cf1586134fe4fa7b62d0b4397fddabd725490f0bf0' 
  AND token = 'W60xQoB+wjOk7k0zAKAJo2T6RjlcwAAcWGyBfexJoew=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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