SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4df0635acc394d45418749cdca9723a416cef3ed3c95946758170bc9718a8082' 
  AND token = 'fqkogGEydiXp4+MpKsBKho3kHIONr6UA968YPVt4Ngw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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