SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '41111a7fb43223e172081ba4141f3c16807392c05108af4e87f1af07c2287cd0' 
  AND token = 'UDcWJCubdvVyDtAYJbXGpfBajklDVqKM6SAuGytYoa0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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