SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7eb8be1a4dd23d5e74f076db5d3d1eeebf147105ec7821f657f9ae8bb53e9a79' 
  AND token = 'KYj2s9NUf0qSlqcOH/OUCguPdzJnk+C7T11bZLp8l6w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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