SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1d56ca5447a810b3dac53ac3aa37e8f38eaae5c7f977cbac9ca37f6220cc4915' 
  AND token = '0OY8nNYPVwezROYePKyEjaymw24WIssUXeIu28swUTs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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