SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '719cc09adc3d782c939de26708846f90d506b0c277fa5adeaa562c0e907f00a2' 
  AND token = 'CS+vTUIfXeu/MyYtO1OuOcHurmiqspUJU1+825V5UYE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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