SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3fb3d6001457ea89f210bf2b18f1c1e91a8a5b8ecb23876bc328bf9253e0d660' 
  AND token = 'U4I2A+p+cPqX89LDNm5nJy8wVJxrpKlIkF0zhLRviHo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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