SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '396f613b3d02d4da7dea1413f0c1204ca9fa5dabfef550cfeed12a0c6fd481f1' 
  AND token = 'fyGCEPCdmnfpYeytOPqFeh4g1DU8cua/JRoTxOu9ZQk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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