SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '143490a9c32a092998bd537a150525ecf6418c94f0b749c4141aeec156eadd6a' 
  AND token = 'bwtt1mx82tCCNm6IEEpHKMawoHJDwTy3XRUlmEPROcU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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