SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'be29aa7141af2a1b408b83c8fa2437949eb7f6dfb0dcaa21ffef9183ced65554' 
  AND token = 'cLPJZmbBWn3dxlKpv+l65xj6lba7zi5Xo/DjZVK4u5Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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