SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9584d3f037aeb83b59be0608348d38d51f3c3bf4b86789051bab72403ccdcc1c' 
  AND token = '2Wzd0SvAyUhnYaKGAYSimPfPJQ0kPESsqoUA1ywigLc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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